Hot answers tagged

86

White has some significant thermal advantages over color. In most cases, this is probably just a benefit in terms of keeping the cabin slightly cooler. In the case of 'plastic' airplanes (those built with composite construction), some airframes require the use of white paint on upper surfaces to keep some elements within limits. Early Diamond Aircraft ...


78

The green coating is a primer (historically zinc chromate, these days zinc phosphate is used as it's less of an environmental hazard) - While you could theoretically fly around like that it is a rather ugly shade of green, so most folks (and airlines) tend to paint their aircraft some other color. So why white? White has a few advantages, but the two ...


66

Paint stripper. Lots of paint stripper. (originally I said thinner, but I have been corrected, it's more accurately called stripper) Seriously though, it's actually not too different to other things that you paint. You need to spray on paint stripper. But, just like when painting the aircraft, it's imperative that you cover up all the delicate systems on ...


46

For unassembled and new planes or planes not yet painted the green/yellow color you see is the anti-corrosive coating on the aluminum ...every unpainted airplane is nominally green from being coated (typically) with an anti-corrosive green zinc chromate or zinc phosphate primer over the aluminum skins. The different shades of green simply tell you ...


44

@RAC and @Hobbes are right. I found a high res photo on defense.gov. The crop below shows WALKWAY and NO STEP instructions indeed. Similar to what you'd find on a jetliner's wing. It makes me wonder though why the person below did not abide. Source: https://tucson.com/news/national/costly-b--bombers-both-tech-marvels-hangar-queens/article_273b0f50-71f6-...


43

There is a discussion on it here that's worth reading but in short the requirements were just different. A few of the key points, The black color on the SR-71 offered some night camouflage in addition to its heat dissipation The Concorde had an Aluminium airframe while the SR-71 had a primarily titanium airframe which could lead to different coating types. ...


32

The engine inlet lip is bare metal to facilitate anti-icing. The area is heated from within using hot engine bleed air. This partial schematic (from Boeing AERO QTR_01.12) shows the engine anti-ice valve, which controls the air supply to the inlet lip: Interesting side note: Even the 787 "no-bleed" system architecture uses bleed air for engine anti-ice.


31

White is indeed chosen for thermal reasons. Gliders use epoxy resins which cure at room temperature and are then tempered at 60°C. This tempering shifts the glass transition temperature to something close to the tempering temperature, so the structure must not be heated under stress to more than this temperature. To limit heating by solar radiation, black ...


31

In addition to the chemical method in Simon's answer, there are mechanical methods, like bead blasting. This method was introduced in the 80s by airforces concerned with the volume of chemical waste generated by their maintenance facilities. It essentially consists of using compressed air to project fine plastic particles ...


30

The prop tips are painted for visibility, to show that the prop is turning. This is especially important when the aircraft engine will be running in close proximity to people on the ground, but is also helpful in alerting the crew of other aircraft that the engine is running, and the aircraft might be moving soon. For visibility, the tip color should be in ...


25

It reduces glare (specular reflection). Football players paint black stripes under their eyes for the same reason. The legend for the paint scheme is excerpted in the inset, upper right. Item #33 "Antiglare areas shall be painted aircraft black." If you read this technical manual, which is publicly available, it describes in the body of the text the use ...


25

It's aluminum "speed tape" being used to run wires around the outside of the fuselage, possibly for load cells or some other kind of sensor related to whatever is being tested and that was impractical to run internally. If you zoom in the image and look carefully at the vertical strip to the right and below TEST, you can make out a dark line in the middle ...


24

(wikimedia.org) Most of the Tu-160 in service are named, much like the B-2 bombers are. The one in the image is S/N: 7-02 "Василий Решетников / Vasily Reshetnikov" named after a WW2 pilot. You can find the names of the other ones on the Russian Wikipedia.


23

That is not unique to WW2 planes, this is fairly common on most prop planes. It is to increase the visibility of a running (spinning) propeller to help people on the ground from accidentally coming in contact with them. The unpainted propellers on the large aircraft may be more related to wartime haste than anything else. (source) From the Mccauley ...


22

Excerpt from McDonnell Douglas MD-11 by Arthur A C Steffen: The remaining eight aircraft were delivered bare-metal with a corrosion protection coating, except for the rudder which has to be painted prior to being installed and balanced, and was completed in the full livery in the carrier's modern paint facilities. The above text is in reference to KLM's ...


22

It's a yellow square that says Willkommen / Welcome. In one case I have seen that additional text was written into the square with a black (removable?) marker. Source This website explains it like this: A yellow welcome panel painted beside each of the passenger boarding doors is now visible on each aircraft. The mark is a flat yellow rectangle, with the ...


21

Of course, in certain situations a plane has to be painted white...or another colour. Concorde had to be finished in a special, highly reflective white paint to mitigate the extreme heating effects that friction caused at mach 2. [It] reaches 127° C at the nose and trailing edge, but the special ‘high-reflectivity’ white paint helps reflect and radiate ...


19

Two reasons for white I've been told many times are: white paint is cheaper than other colours (either because it costs less and/or weighs less) white makes it easier to apply names and logos of other companies when leasing your aircraft to someone else. Saves a trip to the paint shop, instead you just apply stickers. Both make sense, but whether they're ...


19

(Source: airliners.net) The letters read 'air bridge'. The line is used for docking with the air bridge as you suspected. Also see: What are these markings under the passenger door? (...) the position of the alignment marks are not standardized and are carrier specific. It also appears on the silver livery: (Source: planespotters.net) It reminds me of ...


19

At a guess, they're 'walk here' lines, to show where you can walk, with the rest of the airframe being 'don't walk'.


18

Concorde's average skin temperature was 92°C (365K). Calculating the black body radiation using the Stefan Boltzmann law we get 1006W/m². This the maximum heat flux possible with perfect radiation, and very similar to the heat flux of solar radiation, which is also about 1kW/m² at the earth's surface in the absence of clouds (and a bit higher at Concorde's ...


18

They aren't "repair patches" themselves, they are repainted areas where some sort inspection and/or repair was done to the underlying structure, that required removal of the paint in the area. What the inspection or repairs were done? Well, you'd have to have been there to know, but the 737 does have a lot of structural inspection requirements ...


17

Stealth paint doesn't reflect radar, it absorbs it by converting it to heat which is absorbed and dissipated by the airplane's structure. Paint is only one of several Radar Absorbing Materials available. The paints known have suspended balls of ferrous material which absorb radar energy at certain frequencies and convert the radio energy into mechanical ...


17

Most Tu-160's are named after notable Soviet military pilots. English Wikipedia doesn't have a complete list; here's a link to the Russian version. Out of 16 currently active Tu-160's, 9 are named after military or test pilots and 4 after aircraft designers (including famous helicopter designer Igor Sikorsky). The rest, for some reason, bear the names of a ...


15

Not to be a smart-ass, but I think the correct answer is "in accordance with the airframe manufacturer's instructions." Aircraft are generally given a corrosion protective layer (or passivated) at the time of manufacture that usually gives them a green color before they are painted. For this reason, unpainted planes are sometimes called "green" planes. ...


14

Contrary to voretaq7's highly upvoted answer, the green coating in your first image is NOT a primer. It's a spray-on plastic protective coating usually referred to as "Temporary Protective Coating (TPC)". This is used primarily as a barrier to oxidation, as there is a very thin layer of very pure aluminum on the exterior surface of the skin. During ...


13

The 747-400 in the question is rather new in the fleet. It was converted and painted for this role around Jan 2016. The choice is aesthetic because anti-glare paint is nowadays available in all colors, compared to 3 or 4 decades past. So if the tech is there to paint it white, but they've deliberately settled for a retro theme, then it is no longer a matter ...


13

Yes, paint imposes a significant weight penalty on larger aircraft. On commercial airliners, that weight translates to a reduction in cargo, passenger and fuel carrying capacity, and that means less money to be made on every flight. That is why some airlines have chosen to remove most of the paint and opt for the bare-metal look. However, there are tradeoffs ...


12

Why airlines don't put third-party ads on winglets I would assume that a significant part of the answer is that it would look and feel cheap (i.e. not good for the airline's brand image.) They don't usually sell advertising elsewhere on their livery for much the same reason (though they do occasionally dedicate a livery to advertising some charity or some ...


11

White makes it easier to spot another plane in the air, since white shows up well against the ground. This is why many early planes were colored on the bottom half and white/silver for the rest. Of course, this matters much less with modern IFR equipment and doesn't matter really at all with high-altitude jets, but old habits die hard, I guess.


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